Research On Microfluidic Chip-based Device For Automatic Immunofluorescent Labelling Of Cells

For long-term space flight and interstellar travel,it is of great significance in real-time detection and evaluation of radiation damage in space environment.It becomes one of the frontier fields of space biology to evaluate the risk of space radiation damage by perform real-time on-site monitoring of radiation damage biomarkers.Although current researches are focused on applications of microfluidic technologies under such extreme conditions like the space environment,there are still challenges,such as elimination of the influence of microgravity,reduction of power consumption,increasement of automation level and speicificity for biomarker detection,under microgravity.This work presented a portable microfluidic system for automatic immunofluorescent labelling of cells,which enabled highly efficient mixing and programmable manipulation as well,for immunomagnetic beads and lymphocytes.The main contents of this thesis were as follows:1)A micromixer for 3D mixing of immunomagnetic beads and cells was developed;the basic performance of the micromixer was investigeted in this work.2)A microfluidic device for automatic immunofluorescent labelling of cells was established,which consisted of 3D-mixing module and programmable manipulation module for magnetic beads,realized through stepper motors controlled by Single Chip Microcomputer(SCM);the microdevice enabled the automatic immunofluorescent labelling of ?-H2AX in CD4~+ T lymphocytes in 40 minutes under room temperature.3)Microfluidic chip was presented for cell immunofluorescent labelling,including 6 oval reservoirs for storage of sample/reagents and isolation chambers between sample/reagent reservoirs for storage of mineral oil;cells processed on the microchips were feasible for next-step fluorescence detection.4)The automatic immunofluorescent labelling of y-H2AX in CD4~+T lymphocytes irradiated by UVC with different doses was performed on the microfluidic device;experimental parameters were investigated and the radiation dose-response relationship was determined by using flow cytometry,which verified the feasibility of the developed microdevice.This work proposed the microfluidic technology for automatic cell immunofluorescent labelling,which employed immunomagnetic beads as the carriers for sample/reagent mixing and manipulation based on functional microfluidic chip and portable magentic field controller.The developed microfluidic device is portable,automatic,cost-efficient and easy to further integrate detection modules for cell analysis.The whole procedure for microfluidic-based cell immunofluorescent labelling is fast,efficient and can be carried out at room temperature without professional operators.The proposed microfluidic technology is compatible with microgravity conditions,so the presented microdevice can be used as prototype for further development of real-time on-site biomarker detection microsystem utilized in space environment.